SSH keys and jailshell

Hello,
I have two cpanel accounts on two separate machines (one main server, one backup), and I want to rsync my account on the main machine to the backup one. Problem is, I can't for the life of me get server1 to connect to server2 using ssh keys (to automate the rsync without prompting for a password). I contacted my host support who said this was a limitation with jailshell, and they enabled bash on my account while they see what they can do.

The ssh keys work OK now the main server account is using bash instead of jailshell, but considering this is effectively a temporary solution I was wondering if anyone had this problem before and came up with a solution short of using an expect script?